The signing of the contracts coincided with a statement by Petrobras supply director Paulo Roberto Costa that the refinery will cost 23 billion reais—more than triple its previous estimate.

Costa also said the expected start-up date had been delayed to April 2012 from March 2011.

Petrobras and PDVSA completed negotiations for joint construction and operation of the refinery, in Brazil's Pernambuco state, last month. They said they will incorporate the company in Brazil.

Petrobras said the largest of the new contracts, valued at 3.4 billion reais, is for construction services for two delayed coking units and related facilities. It went to combine of Construcoes e Comercio Camargo Correa SA and CNEC Engenharia SA.